At 10 a.m. PT today, Apple CEO Tim Cook will rouse the Apple developer faithful at its annual Worldwide Developers Conference, an event that provides four days of hands-on technical sessions but kicks off with product announcements. Typically, WWDC is the launch site for new versions of Apple's iOS mobile operating system, and everyone expects iOS 7 to debut today, likely with a freshened design to help reduce the foul odor from last year's Apple Maps snafu and a growing sentiment by a segment of the tech pundit community that, after six years, iOS looks dated. A new version of OS X -- 10.9, cat name to be determined -- is also expected to debut.

But no one has a clue of what substantive changes we'll see in iOS or OS X today. Many people also expect Apple to finally announce an updated version of its Mac Pro, the darling computer of software developers that hasn't been significantly updated in three years, pushing many developers to the MacBook Pro line instead.

iOS, OS X, and Apple's device and computer lines are hugely important, and they are what most people think of when you say "Apple." But Apple's been pushing into many service areas, with mixed success and uneven commitment. WWDC 2013 would be an opportunity to show how -- or if -- they relate to each other and give developers and users alike a clue as to the greater Apple ecosystem being developed. Because surely that is what Cupertino is up to. Here are the big areas where Apple's tentacles have been reaching outside its computers and devices business:

Entertainment content

In a nutshell, that's iTunes and its music, podcast, video, e-book, and games delivery business for Macs, Windows PCs, and iOS devices, but not for the hugely popular competing Google Android platform. Apple has long favored building a proprietary ecosystem, and with iTunes, it has done a remarkable job using iTunes and Apple TV, coupled with the AirPlay streaming protocol limited to its devices and to iTunes, to create a simple, flexible home-media system that works very well. A subscription radio extension, which pundits have been calling iRadio, is expected to debut today.

Expanding iTunes' and AirPlay's reach into Android makes sense, especially given Google's faltering Google Play ambitions. But Apple would then lend support to its reviled rival. It's hard to see Apple doing that now; when Apple finally made iTunes available for Windows, it was five years after its Mac debut, during a period of Apple-Microsoft détente and after Apple had assured its own dominance over the music-distribution industry. The politics today with Google aren't as fertile for Android support.

Plus, every platform now offers an iTunes-like mix of entertainment offerings, even if none is anywhere close to achieving iTunes' market success. That suggests having Android, Windows Phone, and other clients for AirPlay and iTunes might not have the same positive effect as the Windows iTunes port did. So it might make more sense for Apple to adopt the DLNA and Miracast protocols on the Apple TV, so non-Apple devices could use it, while Apple's iTunes and AirPlay combo remained the premium approach available only on Apple's own devices.

Electronic ticketing and wallets

The Passbook service introduced in iOS 6 for the iPhone is a handy service for collecting in one place airplane, train, movie, and other tickets, turning the iPhone in a partial digital wallet. Passbook got off to a slow start, and its use today is still primarily for travel tickets, though you can also load affinity cards for stores such as Walgreens. Limiting Passbook to the iPhone -- it doesn't run on the iPad -- struck me as an odd move, given how many travelers have their iPads in hand in airport lounges, but it's true that they always have their phone available.

I suspect Apple intends to evolve Passbook into a true digital wallet for use as a hub to make payments, akin to the credit cards already tied to your iTunes account. Plenty of companies like Square offer such a digital wallet for iOS, so the technology is no longer rocket science but instead ripe for Apple's brand of exploitative improvement -- especially because Google's Wallet service is struggling to gain adoption, given its reliance on the industry installing a new kind of reader terminal and users having NFC-compatible phones.